Composite insulating material.



Pate nted Sept. 24, I90l.

G. KELLY.. COMPOSITE INSULATING MATERIAL.

(Application filed. we 25, 1901.

No Model.)

UNITED STATES GEORGE KELLY, OF MIN COMPOSITE INSU ERALPOINT, WISCONSIN.

LATING MATERIAL.

SPECIFICATION forming part of Letters Patent No. 683,208, datedSeptember 24, 1901.

Application filed Jun'e25,1901- To all whom it may concern:

Be it known that I, GEORGE KELLY, a citizen of the United States,residing at Mineralpoint, in the county of Iowa and State of Wisconsin,have invented a new and useful Composite Insulating Material, of whichthe following is a specification.

This invention relates to a hovel composite material for insulating andother purposes.

The object of the invention is to produce an inexpensive and completelynon-conductive lining for floors, refrigerator-cars, and cold-storageapartments or to prevent the radiation of heat from heated surfaces, andthis end is attained by combining a loose flax fiber (preferablypurified) with a filler of mineg alwool in a loose flocky condition.Both flax fiber and mineral wool are known to be excellent insulators;but the use of mineral wool for insulating purposes is limited by reasonof its tendency to settle when placed in a perpendicular.position-as,for instance, between walls. Besides being one of the best insulatorsknown, if, indeed, it is not actually the best, itis inexpensive, beinga by-product of iron smelting, and therefore the only drawback to itsgeneral use is the dificulty encountered in sustaining it in its properposition. Flax fiber, as already stated, is likewise an excellentinsulator and has no tendency to,settle or sag like mineral wool. Flaxfiber, however, is comparatively expensive, and one of the primerequisites of a commercially successful insulator is cheapness. Thepresent invention is therefore directed to the production of aninsulating material which will be composed in a large part of theinexpensive mineral wool, but combined with flax fiber in a manner tocause the mineral wool to be sustained against that sagging or settlingwhich has heretofore precluded the possibility of its use in manyconnections.

' In the accompanying drawing I have shown a sheet of my insulatingmaterial with the several layers broken away for the purposeof clearlyillustrating the structure.

In producing the material I first provide a sheet or layer of suitableflexible materialas, f orinstance, paper or cloth-which I shalldesignate as the cover-sheet 1, and upon this cover-sheet is spread alayer of loose flax Serial No. 65,981. (No specimens.)

ditions. By preference, however, theflax fiber employed in my insulatingmaterial is first purified to produce a cellulose fiber by any meansknown to those skilled in the art. The peculiarities of this cellulosefiber derived from the flax are its great strength and resiliency andits exceedingly light weight. This is owing to the fact that the fibersare of great length and strength and are of hollow cylindrical form, thetreatment of the flax to produce the pure cellulose fiber serving tothoroughly remove the lignose, lignin, lignone, and lignireose as wellas the gums and carbohydrate which incrust and impregnate the cell wallsand interstices as well as the hollow inside of the tube of a raw oruntreated flax fiber. The removal of these substances from the fibergreatly increases its non conductivity, and each hollow cylindricalfilament becomes an air-cell infinitesimally small, but constituting oneof an innumerable number of air-cells present in the mass of fiber andserving to render the latter an excellent non-conductive material. Thisraw flax fiber or purified cellulose fiber, as the case may be, is, asstated, spread in a layer of the desired thickness upon the-coversheet 1and is indicated in the drawing by the numeral 2. Upon this layer offlax fiber is next imposed a layer 3 of mineral wool in a loose flockycondition. Upon this is imposed a second layer 4 of flax fiber, whichlatter is then covered with a second coversheet 5. The material thusformed is now subjected to sufficient pressure to secure the necessaryinterrelation of the'alternate layers of flax fiber and mineral wool. Itwill be noted that the flax fibers are exceedingly long and that thefibers of the mineral wool are very short, and it is by reason of thepeculiarities of these materials that they are especially adapted forcombined use in the manner stated. In otherwords, these fibrous layersbeing composed, respectively, of long and short fibers becomeinterlocked orinter woven with each other, the peculiar loose fiockycondition of the mineral wool facilitating the penetration of its fibersinto the fibrous layers of flax. The material having fiber iscontemplated under certain conbeen built up of any desired number ofalternate layers of flax and mineral wool, covered, as stated, withpaper or other suitable cover-sl1eets,the insulating-felt thus producedis stitched through to insure the proper retention of its layers. Thelines of stitching are preferably disposed longitudinally of the stripof felt or insulating material adjacent to the opposite longitudinaledges thereof, as shown in the drawing and indicated by the numeral 6.

It will now be seen that I have produced a novel insulating materialcomposed in part of mineral wool sustained and augmented by raw orpurified cellulose fiber and designed for, use in the variousconnections wherein an insulating-felt is available. I desire to beunderstood, however, as reserving the right to effect such variations ofthe hereindescribed embodiment of the invention as may be properlycomprehended within the scope of the protection prayed.

What I claim is- 1. A composite insulating material of the characterdescribed, composed of mineral wool and a sustaining-body of flax fiber.

2. A composite insulating material com.- posed of layers of mineral wooland flax fiber in a loose, dry condition and in intimate relation.

3. A composite insulating material composed of alternate layers ofmineral wool and flax fiber, and means for securing said layers inintimate relation.

4. A composite insulating material composed of alternate layers ofmineral wool and flax fiber, and a flexible cover.

5. A composite insulating material composed of alternate layers ofmineral wool and flax fiber, a flexible cover for said layers, andstitches passing through the several layers and cover.

6. A composite insulating material composed of alternate layers ofmineral wool and flax fiber, from which fiber the gums and lignates havebeen removed.

7. A composite insulating material com, posed of mineral fiber anddegummed and delignated cellulose fiber of flax.

8. A composite insulating material composed of alternate layers ofmineral wool, degummed and delignated cellulose fiber of flax, aflexiblecover for said layers, and stitches securing the layers and cover inintimate relation.

In testimony that I claim the foregoing as my own I have-hereto afiixedmy signature in the presence of two witnesses.

GEORGE KELLY.

Witnesses: PHILIP ALLEN, Jr., FRANK HANSCOM.

